


Callipygian

by Everyday_Im_Preaching



Category: Gravity Falls
Genre: Chubby Dipper, Established Relationship, Intercrural Sex, M/M, Monster!Bill, Multi-limbed Bill, Sex, thigh fucking
Language: English
Status: Completed
Published: 2017-03-22
Updated: 2017-03-22
Packaged: 2018-10-09 04:25:55
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,518
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10403904
Author URL: https://archiveofourown.org/users/Everyday_Im_Preaching/pseuds/Everyday_Im_Preaching
Summary: Dipper is used to late-night visits from the horrorterror that he's dating. On a particularly cold night, he lets Bill in, planning on cuddling with the monster until he falls back asleep.Bill has another plan for the sleepy human.





	

Tapping.

Dipper cracked an eye open, letting his gaze wander to his window. A familiar set of glowing, yellow eyes peered in at him; another tap, soft and quiet against his window, followed by a silent pout. Dipper rolled his eyes, dragging himself from his bed. The cold greeted him like an old friend, curling around his ankles and dipping in between his toes.

“You know, I'd give you a key if you asked,” Dipper murmured sleepily, fingers fumbling for the lock. Four individual hands pressed against the window, fingers long and calloused. A low coo, followed by some affectionate clicking reached Dipper's ears, and he felt a blush ghost across his cheeks as he caught the lock in between chilled fingers.

As soon as the window was unlocked, there was a sharp rattling of the window frame. A whimper. Dipper hushed the creature on the other side, gripping the bottom of the frame and tugging it up with a soft grunt. The wind outside was _freezing,_ biting at his cheeks and nose. The window slammed shut in seconds of being opened, and a set of hands cupped his face, whilst another hooked around his back, drawing him into strong arms.

“Darling, my little sleepy tree. I'm sorry to be calling on you so late,” Bill said softly, voice warm in contrast to his fingers. They stroked his cheeks and jaw, and lips descended on Dipper's with a gentle kiss. The human met the kiss happily. “Look how tired you are, my little mortal.” Another kiss, to the side of Dipper's nose.

“It's okay,” Dipper murmured, wrapping his arms around Bill. He pressed his cheek to Bill's chest, rubbing it against the soft cotton of his shirt there, feeling the scales beneath press against his skin. Fingers stroked his back gently, pinching the cloth here and there, attempting to tug it off from the human. “I like having you here. Bed's still warm.”

 A soft rumbling greeted him, and a kiss was placed to the top of Dipper's head.

“I would be honoured,” Bill told him. His thumbs brushed down the human’s side through the cloth, rubbing at the small chub that had amassed on Dipper's hips. Dipper opened his mouth to yawn, wide and long like an exhausted feline. “So cute.”

“Come on.” Dipper slipped backwards, out of the range of grasping hands. Bill followed him like a puppy, cooing and clicking at him. “Shoes, clothes--” He pointed at Bill's getup of silken, embroidered pants and the mismatched band tee that he wore. “--off.”

“Mm, so eager to get me naked,” Bill teased, voice sounding like the sound of underbrush rustling in the breeze. He pulled his shirt from his body, tossing it away. Pants and clothes went next, leaving him nearly naked. Bill's skin was a mixture of shimmering, silver scales and inky black splotches that twisted their way up from hips to breast. He looked _beautiful_ in the soft moonlight that slipped through the window, dodging the curtains to reach the carpet below.

“Only because I'm cold and want to go to bed,” Dipper told him, yawning again for effect. A set of hands attempted to grab at him once more. The human twisted just out of his reach, doing a belly-flop on his bed. Bill followed him there, leaning his body over the human, dipping down to kiss him softly.

Fingers tugged at his shirt, while a hand slipped around to play with his curls. They twisted in the brown locks as Bill gifted the human with more kisses, warm and sweet. Dipper chuckled, knocking their noses together and responding to the affection with languid kisses. Bill slipped up on to the bed, letting Dipper get comfortable once again beneath his blankets.

“You're not here to sleep, are you?” Dipper asked, cocking an eyebrow. Bill shrugged his too-sharp shoulders, running a hand along the prone form of his human, eyes slanting in deliberation. After a moment, he shook his head.

“No. But you look so tired, I couldn't dare ask anything of you,” Bill replied, rustling Dipper's hair. Dipper smiled sleepily at him, bumping his head against the hand. Eyelids slid closed, and Dipper's lips parted.

“I don't want to leave you wanting,” Dipper whined quietly; Bill clicked at him again, stroking his back once more. The inhuman being pursed his lips, laying his hand on Dipper's lower back.

“I… do have an idea, if you'd entertain me,” Bill suggested, rubbing soothing circles into the human’s back. “It's nothing we've tried before, but it shouldn't take any effort from you.”

“Sounds like my kind of sex,” Dipper teased, lips turning up at the corners. The human nodded, pressing his cheek against the pillow. Bill began to tug at the warm cocoon of blankets, getting a half-angry whine. Dipper shuddered, curling his arms around his chest.

Bill hummed softly to himself, rolling Dipper over onto his belly. He let his fingers trail down Dipper's ass cheeks, murmuring what sounded like a soft prayer. Dipper wiggled his lower half and was rewarded with a kiss to his butt, lips worshipping the curve of it. Fingers slid beneath his waistband and Bill let out a tiny hum. He flattened the band against Dipper's skin before shifting back on the bed so he could kiss the round ass again, massaging it in his palms.

“How was your day today?” Dipper asked, voice thick as he began to doze off. One set of Bill's hands were tugging his pants down slowly, whilst the others were rubbing his lower back. They worked the temporary chill from his body in smooth circles.

“It was less than entertaining,” Bill replied, voice dropping as he frowned. “There are very few humans to trick during the holidays, in a tiny town like this. I think I'll give up on the mischief for now.” He paused. “If… perhaps...” Bill sighed. “...Will you allow me to remain with you? Here? I have no desire to be a burden--”

“--Bill, you aren't a burden. You never will be,” Dipper told him, sleep fleeing his voice for a single moment as the words left his lips. “You're always welcome here. And I'd like it if you'd stay with me.” Dipper turned his head; even exhausted, he looked stern. “I love you, Bill.” A soft clicking rose from behind him; Bill kissed the base of his spine. “Stupid.” Dipper turned back to the pillow, nuzzling it again.

“Thank you,” Bill murmured against his flesh. His boyfriend’s hands wandered down, gently kneading his thighs. “Where's the lube?” he questioned; Dipper flapped a hand at the end table to the right. Bill's body momentarily lifted from the bed and Dipper shuddered as Bill's shadow fell over him.

“I don't know which kind we have,” the human muttered, closing his eyes.

“Looks like the flavoured kind.” Dipper listened to the cap pop open behind him, and he sighed softly, wondering what Bill was up to. “Oh, orange. I know what _I'm_ licking off of you later.” Dipper kicked his legs lazily, trying to catch Bill with his foot; Bill caught it deftly, rubbing the human's ankle.

Bill moved around a bit, leaning off the side of the bed to pick up some pillows that Dipper had kicked off the side of the bed. He hummed happily and began to tuck them beneath Dipper's tummy, lifting his bare ass into the air. The human wiggled his hips slightly and was met with the cool lube being applied to his ass, and smoothed over it.

Fingers slid between his cheeks, teasing his puckered hole before travelling down to cup his balls. Dipper gasped, rolling his hips back. Bill clicked his tongue and pulled his hand away. The human heard the click of a cap again and the soft scent of citrus as Bill spread more of the orange lube on his hand.

“Open up for me a bit,” Bill whispered, voice husky and low. Dipper did as he was asked, furrowing his eyebrows as Bill lathered the lube on the inside of his thighs liberally. After a few moments of massaging it into the tender skin, the hand disappeared again. “Now cross your ankles.”

“Cross my ankles?” Dipper asked. Bill let out an affirmative hum. “Alright, crazy. Whatever you say.” He slipped his ankles over each other, crossing them tightly. Dipper waited patiently as the man behind him had removed all four of his hands, leaving him oddly slick and feeling slightly gross with the amount of the viscous liquid that had been rubbed over his backside. Dipper heard Bill tug his own pants down, rubbing over the scales almost musically.

“Your ass tightens beautifully when you do this,” Bill admitted, bracing two of his hands on Dipper's hips. “And these thighs.” Fingers slipped in between slick thighs, directly below his ass. A few testing prods had a clicking purr rising in Bill's throat, and soon a cock replaced them.

“Are you going to fuck my thighs?” Dipper asked, unconsciously tightening his thighs even more.

“I intend to,” Bill replied; his hips pressed forward, cock slipping between warm, chubby flesh. He let out a choked groan, squeezing Dipper's ass cheeks and pressing his thighs together harder in the same movement he drew back and pushed in again. Dipper let himself rock forward with the motion; he gripped at the sheets to steady himself. Bill was doing his best to not arouse the human; but it was so hard. Dipper was letting out gentle gasps as Bill's cock slid up against his balls and the base of his shaft.

Bill was muttering soft words of devotion into his ear, slipping and sliding between his thighs, squeezing Dipper's ass and letting out a tiny parade of moans and whines directly into his ear. Dipper couldn't help but giggle when the head of Bill's cock popped up from between his thighs, rubbing messily against his stomach.

A tongue pressed wetly against Dipper's shoulder, followed by razor sharp teeth that nipped just hard enough to have the human squirming and quenching the desire to kick Bill in the face. He was fully hard now, thighs tightening imperceptibly each time his boyfriend slipped between his thighs.

“That's it. Steady,” Bill whispered against his ear; his cock was sliding easily between Dipper's thighs, smearing black pre-cum up and down the inside of them. “I know you're tired, oh my excited, sleepy little one. But keep your ankles locked, okay?” Bill pleaded, thrusts harder now; the length of his cock slipped along Dipper's belly, occasionally catching his belly button.

A hand slid beneath Dipper, pressing against his messy belly and drawing a complex formula of nonsensical symbols in the mixture of slippery pre-cum and sweat; Dipper recognised a few. _Love._ Bill wrote against his abdomen. _Protect. Darling._ Dipper slid his own hand over Bill's, pausing the actions and intertwining their fingers, tugging the hand down towards his erection.

Bill let out a long, heavy groan; his lips moved from where they panted next to Dipper's ear to nip and play with the skin at the back of his neck, his hips slapping against Dipper's ass now in satisfaction. Dipper tried to push his hips back to meet the next thrust and was greeted by a hungry groan; Bill's hand slid the rest of the way down, cupping Dipper's erect cock in his palm and squeezing it.

His fingers moved in quick, uneven strokes, just like the jackhammer of his hips. Dipper's voice mixed with Bill's in an obscene, quiet dissonance; raspy gasps mixed with harsh groans and soft, honeyed words. A soft squelching caused Dipper to shudder and curl his toes, whimpering loudly at the disgusting sound. Bill must have seen this as a cry for more attention, because he released one of Dipper's hips to wrap it around the human’s chest, taking a nipple between calloused fingers.

It wasn't much longer before Bill's hips were stuttering; he was sucking in sharp, uneven breaths. His pace became uneven and he released his grip on Dipper to sit up straight, using his hands to grip at Dipper's thighs, squeezing them tightly. He came with a sharp cry, fingernails digging into the human's skin and drawing blood to the surface. A hot splatter fresh cum decorated Dipper's stomach and cock, and he let out a pleading groan.

After a moment, Dipper wiggled his hips, waiting impatiently for Bill to return to reality and take care of him. It didn't take long, and the first thing out of Bill's mouth were a string of quiet, begging apologies.

“I'm so sorry,” Bill apologised, slipping his softened cock from messy thighs. “You poor thing, I didn't even think about it. Here, let me take care of you.” Dipper shrugged, letting his legs fall open; peeking down, he shuddered. His thighs looked _disgusting._ Four sets of equally gross hands gripped his hips and urged him to roll over.

Dipper let out a low groan, but did as he was asked; his hips were still propped up on pillows, giving Bill a perfect view of the mess he'd made. A happy clicking erupted from Bill’s throat.

“Oh, _oh,_ ” he breathed, eyes widening; they were glowing brighter than before. “You look so _b e a u t i f u l._ ” Bill's voice cracked slightly, devolving into static for a brief moment as he surveyed the human. “May I touch you? May I?”

“You just came all over my stomach and thighs,” Dipper growled out, painfully hard at this point. Bill chuckled, fangs flashing at the human as he did so. The human watched in fascination as his boyfriend's mouth widened with an unsettling crack of his jaw, showing the endless rows of sharp teeth. Dipper swore that there wasn't an end to his gullet; just a dark pit that continued for the rest of eternity.

“Very good point.” Bill slid a hand around Dipper's cock again, tugging at it. After a moment, Bill's face settled, lips turned down into a frown. “I'm sorry that I got so excited. I didn't think that I would be so caught up in my own pleasure.” He bent his body at an unnaturally sharp angle, pressing black lips to Dipper's stomach; Bill's tongue darted out to lap up his own seed. “How about I make up for it?”

Dipper raised a leg, hooking it over Bill's shoulder. He grinned at his boyfriend, and Bill cooed softly, reaching a hand up to cradle a chubby cheek. Bill shuffled back on the bed a bit, allowing him a comfortable space to nose Dipper's cock and run his tongue along it. The human moaned, throwing his head back against the sheets.

“Sounds like you aren't ready to go to bed just yet,” Bill murmured, kissing the head of Dipper's cock. The human narrowed his eyes, trying to glare at the man-like creature between his legs. After a moment, he gave up, clenching his fingers in the sheets beneath him and jerking his hips up. Bill was right. Sleep was the last thing on his mind.

**Author's Note:**

> Hello!
> 
> Songs for this fic:  
> Don't Say You Do by Lola Blanc  
> Violence by Meat Market
> 
> My beta is EmberGlows :3
> 
> Want to stay updated? Click [here](http://everyday-im-preaching.tumblr.com/) to stay in the know!


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